Divergence Singularity

Summary

To test out the capabilities of D-Mail in affecting the past, Okabe decides to send a message to himself one week ago using the numbers of a winning lottery ticket (but only enough to win the third prize, to avoid the eyes of the Organization).

After sending the message, he suddenly finds himself in a slightly changed world where he never sent the message to himself, but his friend took down the winning lottery ticket for him one week ago and Kurisu got him a Dr. Pepper. None of the lab members remember anything about the D-Mail he just sent, causing Okabe to wonder why only his memories remain unchanged.